An insulin pump is a medical device that delivers a continuous, measured flow of rapid-acting insulin beneath the skin, a method known as Continuous Subcutaneous Insulin Infusion (CSII). This technology offers an alternative to multiple daily injections, providing a more consistent basal rate and flexibility for mealtime dosing. The first truly practical, wearable models for patient use appeared in the mid-1970s, transforming diabetes care into a more flexible and physiologically accurate system.
Precursors to the Modern Pump
The idea of automatically delivering insulin began in the 1960s with experimental, non-wearable devices. Dr. Arnold Kadish developed the first prototype in 1963, a large device intended to function as an early artificial pancreas. This machine utilized a closed-loop system, automatically adjusting insulin infusion based on sensed blood glucose levels. However, the initial design was immense, similar in size to a large backpack, making it impractical for patient mobility.
Kadish’s system required intravenous access for delivery and relied on complex components, including a venous blood circuit and a laboratory analyzer to measure glucose. A subsequent development was the Biostator in 1974, a sophisticated bedside device weighing approximately 60 kilograms. This machine also featured a closed-loop system, combining continuous glucose monitoring with insulin delivery, primarily for research and hospital settings. These early, cumbersome machines proved the feasibility of continuous, dynamic insulin delivery.
The First Wearable Insulin Delivery System
The transition to wearable devices occurred in the mid-1970s. Inventor Dean Kamen created the AutoSyringe in 1973 while still an undergraduate physics student. This infusion pump was initially used for other medical applications, such as chemotherapy, but was later adapted to deliver insulin.
A parallel development came from Professor John Pickup and his colleagues in London, who began clinical use of a simple, portable pump for CSII in 1976. This device was distinct because it delivered insulin subcutaneously, which was more suitable for long-term therapy than intravenous methods. Pickup’s early model weighed about 159 grams and provided a continuous basal rate with a mechanism for the user to manually deliver a mealtime bolus.
These first-generation commercial pumps, sometimes nicknamed the “blue brick,” were bulky compared to modern standards. They were a monumental advancement, allowing for the continuous delivery of insulin that better mimicked the body’s natural function. The ability to manage the basal rate throughout the day, including phenomena like the pre-dawn blood sugar rise, provided a level of control previously unattainable.
Miniaturization and the Rise of Smart Pumps
Following the introduction of the first wearable pumps, the next two decades focused on miniaturization and increased programming sophistication. By the 1990s, external pumps emerged that were significantly more compact and user-friendly. They introduced features like bolus calculators and the ability to set different basal rates for various times of the day, making pump therapy more appealing and manageable.
A major technological leap occurred with the integration of Continuous Glucose Monitoring (CGM) technology. The first insulin pump to incorporate CGM capability was released in 2003, creating a sensor-augmented pump system. This laid the foundation for “smart pumps” that could react to the user’s glucose data. Further innovation led to the development of the patch pump in 2011, which eliminated external tubing by adhering directly to the skin.
The most significant advancement has been the development of hybrid closed-loop systems, which became commercially available in 2017. These systems, often described as an artificial pancreas, use sophisticated algorithms to communicate between the CGM sensor and the insulin pump. They automatically adjust the delivery of basal insulin based on real-time glucose readings, relieving the user of daily management burdens and improving time spent in the target glucose range.